This invention relates to an automobile assembly, in particular to structural assemblies employed at the front end known as a “front end carrier” or rear end of an automobile and also to assemblies for use as bumper systems. The invention is especially concerned with automobile structural assemblies having a reinforcing member and a structural member which are connected together by means of an adhesive.
An automobile bumper system typically comprises a “bumper beam” and a “bumper fascia”. Typically the bumper beam is bolted to the chassis of the automobile and the fascia is connected to the body panels. An energy absorption unit is typically disposed between the fascia and beam. A bumper beam is typically made of a rigid material, for example steel and aluminium, to provide structural integrity and an impact reaction surface and may act as a reinforcing member in the bumper system. The “bumper fascia” is shaped so as to abut or to be connectable to the energy absorption unit and also to have aesthetic appeal, it being part of the external part of the bumper system. A “bumper fascia” may typically be made of or comprise a molded plastics material.
Energy absorption units (EAU) may be made of metal, for example steel and aluminium, or may be made of plastics material. The EAU compresses or distorts on impact so absorbing the energy of the impact. Conventional plastic bumper EAUs may be assembled for example by heating staking points so as to weld the plastics material of the EAU and the fascia together. This process may however leave undesirable visible marks on the fascia.
The fascia may also be attached to the EAU using mechanical fixing means.
The EAU may be connected to the bumper beam or may be located close to but spaced from the beam. Typically, the EAU may be connected to the beam using mechanical fixing means.
Referring to FIG. 12, a “front end carrier” (21) (hereafter FEC) for an automobile (22) is that part of the body of the automobile which joins the two sides (23 and 24) of the front of the automobile (22) together and is aligned transversely so as to enclose a front, typically engine, compartment (25). The FEC is shaped for aesthetic and functional purposes, and typically houses or is otherwise used to carry one or more of the lighting assemblies, the cooling system and the latch by which the bonnet is secured when closed.
Traditional adhesives do not bond effectively to plastics materials of the type used in FECs and which may be used in bumper systems due to the low surface energy of the plastic materials. As such it is believed adhesives have not hitherto been employed for fabricating FECs, bumper systems and the like.
Adhesives for use in bonding to low surface energy materials are however known. For example U.S. Pat. No. 5,795,657 discloses adhesive compositions which are said to have excellent adhesion to a variety of substrates especially low surface energy polymers. The adhesive disclosed in this document relates to organoborane polyamine complexes and especially complexes wherein the polyamine is reaction product of dye primary amine terminated material and material having at least two groups reactive with primary amine with an excess of primary amine groups over groups reactive with primary amine. The complexes may be used in systems that initiate the polymerization of acrylic monomer to yield acrylic adhesive compositions. Such compositions are said to be useful for bonding low surface energy plastic or polymer substrates. U.S. Pat. No. 5,795,657 refers to organoborane amine complexes used in acrylic adhesives and which may be employed in structural and semi-structural applications including glass/metal bonding and bonding other types of materials together. Reference is made to bonding plastic to a range of types of materials of which one is metal.